Expression of protocadherin 11Yb (PCDH11Yb) in seminal germ cells is correlated with fertility status in men.

Protocadherin 11 Y-linked (PCDH11Y), a member of the cadherin superfamily, is predominantly expressed in the central nervous system, is encoded by the Yp11.2 locus and exists in three isoforms: 11Ya, 11Yb and 11Yc. PCDH11Y is upregulated by retinoic acid signalling and is essential for spermatogonial differentiation and initiation of meiosis. PCDH11Y mediates Wnt signalling, which plays a crucial role in the differentiation of various cell types. PCDH11Y has been implicated in neuronal cell differentiation and proliferation, but its association with spermatogenesis has not yet been addressed. Hence, in order to address the possible role of PCDH11Y in relation to spermatogenesis, the expression analysis of PCDH11Y in the seminal germ cells of fertile and infertile males were carried out employing RT-PCR, western blotting and immunofluorescence analysis. In the present study, PCDH11Yb, but not PCDH11Ya or PCDH11Yc, was expressed in germ cells isolated from the semen of all 13 men with proven fertility. However, in several subjects from various infertility classes, there was complete absence or a significant reduction in the expression of PCDH11Yb. PCDH11Y exhibited prominent localisation on the head and midpiece region of spermatozoa from fertile men, whereas spermatozoa from infertile subjects had either weak or abnormal localisation patterns for PCDH11Y. In addition, downregulation of canonical Wnt signalling was correlated with defective expression of PCDH11Y in spermatozoa of infertile men, as evidenced by downregulation of the Wnt targets C-Myc and C-Jun. In conclusion, expression levels of PCDH11Yb in germ cells in the semen were correlated with the fertility status of men.

Autoimmune Regulator (AIRE) Is Expressed in Spermatogenic Cells, and It Altered the Expression of Several Nucleic-Acid-Binding and Cytoskeletal Proteins in Germ Cell 1 Spermatogonial (GC1-spg) Cells.

Autoimmune regulator (AIRE) is a gene associated with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). AIRE is expressed heavily in the thymic epithelial cells and is involved in maintaining self-tolerance through regulating the expression of tissue-specific antigens. The testes are the most predominant extrathymic location where a heavy expression of AIRE is reported. Homozygous Aire-deficient male mice were infertile, possibly due to impaired spermatogenesis, deregulated germ cell apoptosis, or autoimmunity. We report that AIRE is expressed in the testes of neonatal, adolescent, and adult mice. AIRE expression was detected in glial cell derived neurotrophic factor receptor alpha (GFRα)(+) (spermatogonia), GFRα(-)/synaptonemal complex protein (SCP3)(+) (meiotic), and GFRα(-)/Phosphoglycerate kinase 2 (PGK2)(+) (postmeiotic) germ cells in mouse testes. GC1-spg, a germ-cell-derived cell line, did not express AIRE. Retinoic acid induced AIRE expression in GC1-spg cells. Ectopic expression of AIRE in GC1-spg cells using label-free LC-MS/MS identified a total of 371 proteins that were differentially expressed. 100 proteins were up-regulated, and 271 proteins were down-regulated. Data are available via ProteomeXchange with identifier PXD002511. Functional analysis of the differentially expressed proteins showed increased levels of various nucleic-acid-binding proteins and transcription factors and a decreased level of various cytoskeletal and structural proteins in the AIRE overexpressing cells as compared with the empty vector-transfected controls. The transcripts of a select set of the up-regulated proteins were also elevated. However, there was no corresponding decrease in the mRNA levels of the down-regulated set of proteins. Molecular function network analysis indicated that AIRE influenced gene expression in GC1-spg cells by acting at multiple levels, including transcription, translation, RNA processing, protein transport, protein localization, and protein degradation, thus setting the foundation in understanding the functional role of AIRE in germ cell biology.